PDBsum entry 3ess

Transferase,toxin

PDB id: 3ess

Contents

Protein chain

199 a.a.

Ligands

18N

Waters ×443

PDB id:

3ess

Name:

Transferase,toxin

Title:

Catalytic fragment of cholix toxin from vibrio cholerae in complex with the 1,8-naphthalimide inhibitor

Structure:

Cholix toxin. Chain: a. Fragment: c-terminal catalytic domain (unp residues 459 to 665). Engineered: yes

Source:

Vibrio cholerae. Organism_taxid: 666. Strain: tp. Gene: chxa, toxa. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.19Å R-factor: 0.132 R-free: 0.154

Authors:

A.R.Merrill,R.Jorgensen

Key ref:

Z.Turgeon et al. (2009). Yeast as a tool for characterizing mono-ADP-ribosyltransferase toxins. Fems Microbiol Lett, 300, 97. PubMed id: 19793133

Date:

06-Oct-08 Release date: 15-Sep-09

Protein chain

Q5EK40  (CHXA_VIBCL) -  Cholix toxin from Vibrio cholerae

Seq: 666 a.a.

Struc: 199 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.4.2.36 - NAD(+)--diphthamide ADP-ribosyltransferase.
• Reaction: diphthamide-[translation elongation factor 2] + NAD⁺ = N-(ADP-D- ribosyl)diphthamide-[translation elongation factor 2] + nicotinamide + H⁺

diphthamide-[translation elongation factor 2] + NAD(+) = N-(ADP-D- ribosyl)diphthamide-[translation elongation factor 2] + nicotinamide + H(+) (Bound ligand (Het Group name = 18N) matches with 50.00% similarity)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

Fems Microbiol Lett 300:97 (2009)

PubMed id: 19793133

Yeast as a tool for characterizing mono-ADP-ribosyltransferase toxins.

Z.Turgeon, D.White, R.Jørgensen, D.Visschedyk, R.J.Fieldhouse, D.Mangroo, A.R.Merrill.

ABSTRACT

The emergence of bacterial antibiotic resistance poses a significant challenge in the pursuit of novel therapeutics, making new strategies for drug discovery imperative. We have developed a yeast growth-defect phenotypic screen to help solve this current dilemma. This approach facilitates the identification and characterization of a new diphtheria toxin (DT) group, ADP-ribosyltransferase toxins from pathogenic bacteria. In addition, this assay utilizes Saccharomyces cerevisiae, a reliable model for bacterial toxin expression, to streamline the identification and characterization of new inhibitors against this group of bacterial toxins that may be useful for antimicrobial therapies. We show that a mutant of the elongation factor 2 target protein in yeast, G701R, confers resistance to all DT group toxins and recovers the growth-defect phenotype in yeast. We also demonstrate the ability of a potent small-molecule toxin inhibitor, 1,8-naphthalimide (NAP), to alleviate the growth defect caused by toxin expression in yeast. Moreover, we determined the crystal structure of the NAP inhibitor-toxin complex at near-atomic resolution to provide insight into the inhibitory mechanism. Finally, the NAP inhibitor shows therapeutic protective effects against toxin invasion of mammalian cells, including human lung cells.